In history, the early modern period of modern history follows the late Middle Ages of the post-classical era. Although the chronological limits of the period are open to debate, the timeframe spans the period after the late portion of the post-classical age (c. 1500), known as the Middle Ages, through the beginning of the Age of Revolutions (c. 1800) and is variously demarcated by historians as beginning with the Fall of Constantinople in 1453, with the Discovery of America in 1492 or the Renaissance and ending around the French Revolution in 1789. From a global standpoint, the most important feature of the early modern period was its globalizing character — it witnessed the exploration and colonization of the Americas and the rise of sustained contacts between previously isolated parts of the globe. The historical powers became involved in global trade. This world trading of goods, plants, animals, and food crops saw exchange in the Old World and the New World. The Columbian exchange greatly affected almost every society on Earth.